Amazon has Sahale snacks. and the Skippy Squeeze tube, but it's 9oz. they also have the small
round .5oz containers that you get in restaurants for breakfast, where the top peels off for a single serving of pnut butter. I forgot about those, but you have to order in bulk. and the tubes are sold in 12 paks. On Google I found single serving Skippy Squeeze Stix, which is very small and looks to be take aboard-able, but I can't find those yet.